A certain crane shall hold some objects which have the shape of a prism. These prisms have an isosceles triangle as base:The shaded area is the prism (the picture shows a cut through it). The crane has two "arms" which shall hold these prisms by pressing them from each side. These forces are the red ones in the sketch and they work right-angled to the side-faces of the prism(s). Task 1:

Depending on the static friction value μ, the prisms the crane is able to carry are limited to those which have certain angles α. Get an equation which shows the relation between μ and the possible α's; solved to α. Something like this: "α>2·μ".

Task two:

Which force must the crane excert on a certain prism to be able to carry it? Derive a nice formula which contains all the variables à la "F=m+g·μ^α-45"

Put all the stuff together and post your solution with explanation here!